The present invention relates to a surface treatment equipment including a power transmission mechanism allowing a surface treatment cage, storing an object to be processed thereinside for performing surface treatments such as a corrosion-proof, washing, barreling, and plating treatments, to be rotatable and vertically movable in a pressure-resistant tank in a vacuum.
Patent Document 1 discloses a prior art washing equipment washing an object to be washed by rotating and vertically moving in a washing tank thereof. In such a washing equipment, a lower end side of a drive shaft is inserted into the washing tank, and an upper end side of the drive shaft is protruded from the washing tank. Such an upper end side of the drive shaft is connected with a vertical movement mechanism allowing the drive shaft to be vertically movable. A rotation drive mechanism allowing the drive shaft to be rotatably movable is disposed to an upper end of the drive shaft, and a rotation table is disposed to a lower end of the drive shaft through a rotation transmission mechanism transmitting driving force of the drive shaft.
The rotation drive mechanism is operated to rotatably drive the drive shaft while the vertical movement mechanism is operated to vertically move the drive shaft in a state that the object to be washed is secured on the rotation table, so that the object to be washed is rotatable and is movable up and down. Accordingly, the object to be washed rotates and/or moves up and down, so that washing operation is performed. The washing equipment disclosed in the Patent Document 1 is used based on a premise that the inside of the washing tank is at a normal pressure.
On the other hand, in a case where washing operation is performed in a state that the washing tank maintains vacuum thereinside, good effect is obtained as is known. For example, in a case where ultrasonic cleaning is performed in a state that the washing tank is in the vacuum, not only an ultrasonic wave is less attenuated compared to a case of performing the ultrasonic cleaning at the normal pressure, but also a washing effect is enhanced by exhausting the air adhered to an undulated area. Moreover, in a case where objects to be processed contact one another or are placed one on another in the surface treatment operation excluding the washing operation, for example, plating, performed in the vacuum, a surface treatment agent permeates small portions, thereby uniformly performing the surface treatment.    Patent Document 1: Japanese Patent Publication No. S63-24754